The primary aim of this proposal is to investigate the development of reading ability and the processes underlying reading ability, using specific event-related potential (ERP) and behavioral measures, in children at risk for a reading disability (RD). Development will be investigated longitudinally over a five year period from approximately 5 to 10 years of age. A second aim is to investigate the development of subtypes of children with RD, in particular, children with and without attention deficit disorder (ADD). A third aim is to further replicate and cross-validate the findings from the first funding period of this project (1983-1986). The specific ERP and behavioral test procedures and measures to be used were identified in research conducted during the first three-years of this project. These specific measures were uniquely associated with either RD or ADD. Both types of test procedures and measures are appropriate for young, prereading children. The behavioral measures are derived from simple naming, learning, and memory tests. The ERP test procedures are selective attention tasks ("games") requiring either selective color or letter processing. As in our previous work, the ERP measurements will assess the time course and scalp distribution (within and between the hemispheres) of neural information processing as a function of these tasks. The ERP waveform will be considered as a complex indicant of neural information processing. All points of the waveform will be measured and analyzed, although specific measures differentiating RD and ADD children in our previous work will be the bases of specific hypotheses. The research is of potential significance in that it should result in objective, electrophysiological methods for differentiating between young, prereading children who may develop various subtypes of RD, particularly RD with and without ADD. It also should provide information about the development of brain processes eventually involved in reading. Such information would be of considerable importance in the understanding, diagnosis and treatment of the neural deficits which may underlie the development of problems in reading and attention.